1. Field of the Invention
The present invention relates to a semiconductor arithmetic circuit, and in particular, relates to a highly functional arithmetic circuit which is employed in image processing and the like.
2. Background Technology
In concert with the development in multimedia technology, the need for operations which handle image data has increased. Image data are expressed as picture element data which are fundamentally arrayed in two directions, so that the amount of such data is extremely large, and when operations were conducted one by one using conventional microprocessors, this required a great deal of time. In particular, this presented large problems in image processing operations which required real time responses, such as robotic applications, and a technological breakthrough was required.
Methods for solving these difficulties were widely proposed in which identical arithmetic circuits were provided for each picture element, and operations were conducted in which the data of the surrounding picture elements was incorporated into the position of each picture element. Since operations at each picture element were conducted in parallel, high speed processing was possible. However, in this method, the scale of the arithmetic circuitry required to conduct such advanced operations was large, and the surface area occupied by one picture element was large, so that there was a problem in that the integration density of the picture elements could not be increased. That is to say, the problem was that it was impossible to increase the resolution of the image. In particular, extremely complex circuitry was required in order to conduct operations such as the reduction of noise by averaging or edge accentuation in order to increase the visibility of the image, so that it was difficult to achieve both an increase in picture element density and an increase in the resolution of the incorporated image.
The present invention solves the problems described above; it has as an object thereof to provide a semiconductor arithmetic circuit which makes possible edge accentuation processing, edge detection processing, and noise removal by means of averaging processing of an image, using extremely simple circuitry.
In the present invention, in a semiconductor arithmetic circuit which is provided with an amplifier circuit in which an input terminal is connected to the gate electrode of at least one MOS type transistor, a first signal input terminal which is connected via a first switching element with the input terminal, and a plurality of second signal input terminals which are connected to the input terminal via capacity elements; a mechanism is provided for opening the first switching element in a state in which a first signal voltage is applied to the input terminal and a predetermined second input signal voltage group is applied to the second input terminals, and subsequently, for applying a predetermined third input signal voltage group to the second signal input terminals, and the amplifier circuit is a voltage follower circuit constructed using a source follower circuit constructed using MOS type transistors, or a arithmetic circuit employing MOS type transistors in the input stage.
It is characteristic that the third signal voltage group all have a single value and this value is equivalent to the first signal voltage. Furthermore, it is characteristic that the first signal voltage and the second signal voltage group are signals obtained from a group of photo sensors arranged two-dimensionally, or signals obtained in this manner which have been subjected to predetermined arithmetic processing.
Furthermore, it is characteristic that the first signal voltage is a signal obtained from a photo sensor at a predetermined position, or such a signal which has been subjected to predetermined arithmetic processing, and that the second signal voltage group comprises signals obtained from a group of photo sensors adjoining this photo sensor at a predetermined position, or signals obtained in this manner which are subjected to predetermined arithmetic processing.
The output terminal of the amplifier circuit is connected to at least one of the second input terminals via a second switching element.
Furthermore, the semiconductor arithmetic circuit of the present invention is provided with an analog data storage circuit and a mechanism for switching the connections, and the output value of the amplifier circuit is stored in at least a portion of the analog data storage circuit, and the output value stored in this manner is again transmitted to the input terminal using the mechanism for switching the connections.
The semiconductor arithmetic circuit described above constitutes one block, and these blocks are arranged in two dimensions, and furthermore, at least one photo sensor is provided within such a block.
By means of the present invention, it is possible to realize edge accentuation processing, edge detection processing and noise removal as a result of averaging processing of the image, using extremely simple circuitry, and it is possible to achieve high functionality while simultaneously improving the image quality of the two-dimensional image sensor. By means of this, it is possible to conduct image processing in real time.
By means of employing the semiconductor arithmetic circuit of the present invention, it is possible to execute image processing, which previously required an enormous amount of time, in a short period of time, and moreover, using simple hardware. Accordingly, the applications thereof are extremely broad, from multimedia applications to robots having a wide varieties of functions.